1. Field of the Invention
The present invention relates to a washing machine equipped with bulk tanks according to the preamble of the first claim.
Washing machines, such as laundry washing or washing/drying machines, are currently available which are equipped with tanks containing sufficient quantities of washing agents, e.g. detergents, softeners or the like, that do not require the user to refill the machine before every working cycle; for this purpose, these tanks are usually arranged in the lower part of the machine and have volumes such that they can contain sufficient quantities of washing agent for several working cycles of the machine; for this reason they are called “bulk tanks”.
2. The Prior Art
Tanks of the above-mentioned type are described, for example, in British patent GB 2 214 524 in the name of INDUSTRIE ZANUSSI S.p.A., and are provided in the form of disposable bags made of deformable plastic which are positioned on the bottom of the washing machine and which supply the tub supply feedbox as necessary. Once exhausted, said bags are replaced with new bags. The cost of bag replacement, however, must be added to the cost of the washing agent, and therefore this solution cannot be considered to be optimal.
For this reason, other types of tanks have been conceived which are rigid containers secured to the bottom of the washing machine, e.g. like those described in European patent EP 0 379 950 in the name of MIELE & Cie GmbH, which are gradually emptied as the washing agent is supplied to the tub.
These tanks are normally filled up before having become completely empty, in order to avoid the risk that a wash cycle is carried out without washing agent.
However, this solution is affected by the problem that the prolonged presence of washing agent in the tank may cause scale and dirt build-up, thus jeopardizing the correct operation of the washing machine.
Rigid tanks suffer from this drawback, unlike disposable bags, which are not affected by this problem because once exhausted they are replaced with new ones.
It follows that a user wanting to clean the rigid tank will be compelled to remove it beforehand from its housing in the machine. This task is not easily done, and implies that the tank must have certain characteristics: first of all, the connections between the tank and the washing machine (e.g. the washing agent supply ducts) must be removable; secondly, the tank must be mounted in the front of the machine, and its shape and extension must be such as to allow it to be removed and re-inserted into its housing; in this respect, it should be noted that the front dimension of the machine is partially occupied by the drum, and therefore the size of the rigid tank known in the art, when removable, cannot be very big; it follows that a removable tank will have a reduced capacity.